I. Field of the Invention
The present invention relates to the field of subterranean pumps, particularly pumps for decanting light oils and other subterranean liquids which are floating below ground on the water table. Generally classified in U.S. Class 166, subclass 372.
II. Description of the Prior Art
Prior patents for removal of hydrocarbons floating on ground water include: U.S. Pat. No. 4,761,225 to Breslin; U.S. Pat. No. 4,273,650 to Solomon; U.S. Pat. No. 4,469,170 to Farmer; U.S. Pat. No. 4,497,370 to Breslin; U.S. Pat. No. 4,527,633 to McLaughlin; U.S. Pat. No. 4,546,830 to McLaughlin; U.S. Pat. No. 5,207,897 to Baird; U.S. Pat. No. 4,625,801 to McLaughlin; U.S. Pat. No. 4,663,037 to Breslin; U.S. Pat. No. 4,678,040 to McLaughlin; U.S. Pat. No. 4,746,423 to Moyer; U.S. Pat. No. 4,934,458 to Warburton; U.S. Pat. No. 4,998,585 to Newcomer; U.S. Pat. No. 5,261,791 to Goguen.
Virtually all such devices float on the water so that they are subject to sticking in the well bore.